Scaffolding element having relatively movable parts



W. BLANK May 22, 1962 SCAFFOLDING ELEMENT HAVING RELATIVELY MOVABLE PARTS 2 Sheets-Sheet 1 Filed Nov. 28, 1958 Int H7102? mu. m

W. BLANK May 22, 1962 SCAFFOLDING ELEMENT HAVING RELATIVELY MOVABLE PARTS 2 Sheets-Sheet 2 Filed Nov. 28, 1958 W N W on f N ,1 L W Miehm Ga United States Patent 3,035 805 SCAFFOLDING ELEMENT HAVING RELATIVELY MOVABLE PARTS Wilhelm Blank, Helmond, Netherlands, assignor to Otto Hinze, Hannover-Kleefeld, Germany Filed Nov. 28, 1958, Ser. No. 777,154 Claims priority, application Germany Dec. 3, 1957 4 Claims. (Cl. 248-354) Lengthwariable scaffolding elements in the form of uprights and beams are of great importance for the construction of formwork for reinforced concrete. Scaffolding elements, particularly formwork-carrying beams have been developed, which are assembled from individual elements so that they can be varied in length and can be cambered. Moreover, formwork-carrying beams for bridging smaller spans are known which consist of element which are not aligned in the longitudinal direction of the beam but overlap by being arranged one over the other, one beside the other or one in the other. The so-called telescopic formwork-carrying beams can be adapted to the required spans in a simple manner. These beams can also be given a slight camber in the shape of a circle of an are. This camber is then more or less eliminated in dependence on the load acting on the beam. The camber is suitably chosen so that a slight rise remains in the carrying structure under a small load but this rise is insignificant in view of the smaller spans.

The relatively movable parts of known beams are connected in such a manner that they can be lowered before the formwork is removed. Enveloping wedge connections have been disclosed as connecting elements. These wedge connections have been used particularly with beam elements having the same profile height. Moreover, pushin wedges have been used as connecting elements particularly in beams having elements which have different profile heights and are pushed one into the other to a larger or greater extent to vary the length. The locating means consisting of wedges provide a frictional connection between the relatively slidable parts of the beams. This frictional connection, however, is not sufiicient to take up substantial shear or tension in the longitudinal direction. Any tensile or compressive forces acting in the longitudinal direction of the beams will be taken up by additionally provided supports. or braces.

In addition to the above-mentioned scafiolding elements in the form of formwork-carrying beams, lengthvariable uprights are known, which consist generally of elements which have approximately the same profile height and can be pushed one into the other and which can be relatively adjusted in steps. For this purpose one or both of the parts to be pushed one into the other have apertures which are arranged in rows and through which split pins or fiat bars are pushed to provide a tensionand compression-resistant connection between the relatively displaceable parts. Such uprights are usually of tubular shape. In addition to these uprights consisting of hollow sections, the length of which can be varied in steps, length-variable uprights of timber, of rectangular cross-section, are in general use. The span is adapted to the requirements by the use of two timber beams arranged one beside the other. After the adaptation the squared timbers are firmly interconnected. The use of such uprights involves considerable labor costs. Besides, these uprights must generally be held against the load to be supported by driving in wedges below them. It is known that timber uprights are subjected to considerable wear and can be used only a few times.

Based on the recognitions-that length-variable formwork-carrying beams having relatively movable parts are frequently subjected to compressive or tensile forces acting in the longitudinal direction of the beam and that the beam can also be used as an upright if it is constructed to resist tension and compression in order to meet this requirement, furthermore, that length-variable uprights for the formwork for buildings are usually constructed to be variable in length in steps, the problem arises to construct scaffolding elements which can be used as beams and uprights in accordance with the above and scaffolding elements comprising relatively movable parts are characterized according to the invention by the arrangement of continuously adjustable, self-locking frictional setting, adjusting and locating means, which extend through the relatively movable parts of the scaffolding element transversely to the longitudinal direction thereof and which can be moved to and fixed in different positions.

Thus, scaffolding elements which can be continuously varied in length and comprise relatively movable parts can be relatively located in all positions in such a manner that they can take up a load acting transversely to their longitudinal direction as well as tensile and compressive forces acting in their longitudinal direction. In accordance therewith the scaffolding elements constructed according to the invention can be selectively used as an upright or as a beam. For this reason the additional supports for taking up forces acting in the longitudinal direction of formwork-carrying beams, which supports were needed where the known telescopic beams were used, are no longer required, particularly in conjunction with the formwork of sleepers or the like.

According to the invention the continuously adjustable self-locking frictional setting, adjusting and locating means are constructed as wedges. The relatively movable parts are formed with appropriate apertures for receiving the wedge-shaped setting adjusting and locating means so that two apertures in each of the relatively movable parts of the scaffolding elements at least partly overlap corresponding apertures of the other part throughout the setting, adjusting and locating range. This measure enables 'a change in the length of the scaffolding element by means of the wedges even under load because the lock between the movable parts will not be removed until the following wedge is driven to vary the overall length of the element.

It is suitable if the apertures in at least one of the relatively movable parts are preferably arranged one behind the other in at least one row and if the spacing of the apertures in the longitudinal direction of the scaffolding element is smaller than the rise of the wedge of the setting, adjusting and locating means.

Where telescopic hollow sections of different heights, which can be pushed one into the other, are used as scaffolding elements, the apertures for the setting, adjusting and locating means which extend through the relatively movable parts of the scaffolding element transversely to their longitudinal direction must be equally spaced from the top engaging faces in the movable parts. This is essential to avoid compressive forces from acting on the scaffolding element if it is used as a formworkcarrying beam when lowered because in the lowered element the movable parts include an angle with each other so that there is an increased danger of buckling under compressive stress.

Known scaffolding elements, in which the relatively movable parts are constructed as open C-sections, the free flanges of which are connected by spaced webs, can be used according to the invention as beams and/or uprights if one of the movable parts has apertures which are disposed on both sides of the webs and have an extent of one rise of the wedge in the longitudinal direction of'the scaffolding element and the other part has apertures which are arranged in rows and spaced by less than the rise of the wedge. I

Because the scaffolding elements consist of relatively thin-walled material it will generally be necessary to reinforce the relatively movable parts adjacent to the apertures.

The drawing shows by way of example an embodiment of the scaffolding element constructed according to the invention.

FIG. 1 shows first of all the side view of a lengthvariable telescopic scaffolding element.

FIG. 2 shows that part of the construction of FIG. 1 in which the parts of the scaffolding element overlap.

FIG. 3 shows a portion of the inner part of FIG. 1.

FIG. 4 is an end view of the scaffolding element of FIG. 1, partly in vertical section taken on line IVIV.

FIG. 5 shows by way of example an embodiment of a wedge-shaped setting, adjusting and locating means.

FIG. 6 shows an example of a formwork construction using scaffolding elements constructed according to the invention.

FIG. 7 shows the formwork for a sleeper, comprising elements according to FIG. 1.

FIGS. 8 and 9 show means for fixing formwork-carrying beams to auxiliary beams.

In FIGS. 1 to 4-, 1 is the outer part and 2 the inner part of a telescopic scaffolding element consisting of open O-sections. The ends of the inner and outer parts are provided with bearing claws 3 and 4. The supports are constructed in known manner and welded or screwed to the open C-sections. Tie sheets 9 for stiffening are arranged at the free flanges of the inner part 2. Spaced strip iron reinforcements 5 and 6 are provided on the outer part 1 to connect the free flanges of the C-section and extend around the major part of the C-section as shown in FIG. 4. These reinforcing strips provide supports for the wedge-shaped setting, adjusting and locating means 14. The reinforcements 6 are bulged out in the form of eyes below the beam part 1, to receive the wedge 10, under the action of which the top faces of parts 1 and 2 are forced against each other to hold the parts 1 ad 2 together. As has already been proposed the part 10 may be guided in a longitudinal slot of the beam part 1 in such a manner that it cannot be lost even in transit and when the beam is knocked down. The outer part 1 is formed with slots 7, 8 which are on the level of the reinforcements 5 and 6 and extend in the longitudinal direction of the beam. These slots are dimensioned so that the wedges 14 can be inserted throughout their length on both sides of the reinforcements. In that portion of the inner part 2 which is pushed most deeply into the beam part 1 the gap between the open flanges is bridged by a fiat bar in the form of .a strap 11. The strap is welded to the free flanges of the inner beam part and comprises apertures 12, 13 arranged in rows. When the scaffolding parts are pushed one into the other, two apertures of the inner part 2 overlap two apertures 7, 8 of the outer part 1 so that .wedges 14 having a small rise can be inserted into these apertures. By driving the wedge 14 as far as to its stop into two partly overlapping apertures the two scafiolding parts 1, 2 will be relatively displaced to such an extent that two other apertures in the inner and outer parts come into registry sufficiently to enable another wedge ,14 to be driven into these apertures. Thus, two wedges .are sufficient for a-relative displacement of the scaffolding elements 1, 2 against the force acting thereon even if they are under a compressive or tensile load acting in the longitudinal direction of the elements. The wedges 14 can only be inserted into the apertures of parts 1 and 2 if the apertures overlap in the longitudinal direction of the beam. To this end it is necessary, if the scafiolding element is used as a formwork-carrying beam, to

drive in the wedge 10 first because in the lowered conjdition, when there is no connection by the wedge 10, both parts 1, '2 of the beam include an angle with each other so that the apertures cannot fully register.

The angles which form the bearing claws 3, 4'and are firmly connected to the beam parts are suitably coni structed to enable the application of longitudinally acting compressive forces on the several parts of the scaffolding element with the aid of a crowbar or another implement to enable 'the removal of the formwork without damage to the fresh concrete if the claws 3, 4 have been clamped in the wall.

The embodiment shown in FIG. 6 illustrates the application of the scaffolding elements constructed according to the invention as uprights 15 to 18 in conjunction with the scaffolding element 19 used as a lowerable formworlc-carrying beam. The formwork-carrying beam 19 consists in this embodiment of three relatively movable parts, which are interconnected in the same manner to provide for a larger span. Rectangular auxiliary beams 20, 21 provided between the uprights 15, 16 and the beam 19 are engaged by the scaffolding elements and transmit compressive forces to the formwork-carrying beam 19 under the wall pressure and to the uprights 15, 16 under the ceiling pressure. The dimensions of the auxiliary beams 20, 21 are determined by the profile height of the formwork-carrying beams and of the similarly constructed supports and by the arrangement and dimensions of the bearing claws. The uprights 17, 18 are similarly located by auxiliary beams 22, 23, 24, 27. Auxiliary beams 25, 26 are also disposed between the fioor 31 and the uprights 15, 16. The auxiliary beams 24 to 27 are aflixed to the floor and held against displacement. WVhen concrete is poured into the spaces 28, 29 to form the side walls of the finished building, considerable compressive forces act on the scaffolding elements 15 to 18 disposed on both sides of the spaces. Besides, when the concrete ceiling 30 is formed together with the pouring of concrete into the spaces 28, 29, an additional pressure is exercised on the uprights 15 to 18. The uprights 15, 16 must take up from the ceiling 30 the entire pressure transmitted to the latter by the formwork-carrying beams 19 and the auxiliary beams 20, 21. It is apparent from the arrangement that additional supports for the ceiling 30 and for the formwork-carrying beam 19 are not required. As the scaffolding elements can take up both tensile and compressive forces the entire formwork is constructed with the aid of similarly constructed scaffolding elements.

Similar stresses as shown in the embodiment of FIG. 6 are apparent from the showing of FIG. 7, where a formwork for a concrete ceiling 32 having a strong sleeper 33 comprises the scaffolding elements 34, 35, forming formwork-carrying beams, and the elements 36, 37 forming uprights. In this embodiment too the beams 34, 35 and the uprights 36, 37 are similar elements constructed according to the invention. Auxiliary beams 40, 4-1 for the fixation of the beams and for transmitting forces from the beams to the uprights are again provided between the upright elements and the beam elements. A ring of beams 42 is provided as a support for the formwork at the lower end of the sleeper 33 and is connected to the scaffolding elements 36, 37 so that the compressive forces acting on the ring are transmitted to the said two scaffolding elements. Wedge connections according to FIGS. 8 and 9 can be used in a simple manner to aflix the supports to the auxiliary beams. FIG. 8 shows the end of an inner part 43 with the bearing 44 affixed thereto. The bearing 44 is formed with two apertures 48 and. 49. Wedges 46 are inserted. through each of said apertures in dependence on' the width of the auxiliary beam 45 so that the auxiliary beam 45 is firmly forced against the bearing claw 44. To this end an abut merit 47 is arranged inside the hollow G-section and is engaged by the wedge 46. V

The construction of the scaffolding elements which are continuously variable in length shown in the drawing is conceivable for all composite beams the parts of which consist of hollow sections. Besides, the setting, adjusting and locating means according to the invention can be used in like'manner for scafiolding elements which are arranged one beside the other rather than one in the other so that they are longitudinally displaced one beside the other.

For use as formWork-carrying beams of high carrying capacity the scaffolding elements can readily be of cambered construction and can nevertheless be used also as uprights if a section is chosen which provide a large moment of resistance to buckling in the direction of the camber.

The possibility of using scaffolding elements constructed according to the invention as beams or uprights affords a considerable economic advantage because the need for separate stocks are avoided. The scafiolding elements may mainly be used as beams or as uprights, as required, so that their useful life Within predetermined periods is much increased.

I claim:

1. Telescopic scaffolding element, comprising, in combination, an elongated hollow outer part having a C- shaped cross-section; an elongated inner part having a C-shaped cross-section and a portion located in said outer part longitudinally movable therein, said outer and inner parts having two parallel staggered rows of longitudinally spaced apertures located to overlap each other; first detachable wedge means located in overlapping apertures of said inner and outer parts and extending transversely to said parts to lock said parts against relative longitudinal movement, said first wedge means being adapted to be inserted into said apertures in differently expanded positions on said inner and outer parts, the effective height of said wedge means in longitudinal direction being at least equal to the distance between two apertures in the respective row of apertures; and second wedge means detachably located between said inner and outer parts and being movable in longitudinal direction to press said parts transversely against each other into an abutting position to block relative angular movement of said inner and outer parts so that the telescopic scaffolding element is capable of gradual reduction in length in upright position by operation of said first wedge means, and of gradual lowering in horizontal position by operation of said second wedge means, whereby the telescopic scafiolding element can be used to support concrete molds in horizontal and vertical positions, said second Wedge means being located opposite lateral walls of said inner and outer parts so that the other lateral walls of said inner and outer parts abut each other, said rows of apertures in said inner and outer members registering with each other when said other lateral Walls abut each other.

2. A telescopic scaffolding element as set forth in claim 1 wherein said apertures are longitudinal slots; and wherein said first Wedge means are flat Wedges.

3. A telescopic scaifolding arrangement as set forth in claim 1, and including straps connecting the free ends of the C-shaped cross section of said inner and outer parts; and wherein the 0-shapes of said inner and outer parts are open on the same side of the telescopic scaffolding element.

4. A telescopic scaffolding element as set forth in claim 1, and including reinforcing members embracing at least part of the periphery of said outer part, said outer part being formed with longitudinal slots in the region of said reinforcing members; and wherein said second wedge means have T-shaped cross-section including a transverse portion located between said inner and outer parts, and a Web portion passing through the respective slot in said outer part and abutting the respective reinforcing member.

References Cited in the file of this patent UNITED STATES PATENTS 844,385 Mommertz Feb. 19, 1907 1,757,312 Kahn May 6, 1930 FOREIGN PATENTS 611,261 Great Britain Oct. 27, 1948 463,471 Germany July 28, 1928 635,044 Germany Sept. 10, 1936 764,943 Germany July 27, 1953 917,961 Germany Sept. 16, 1954 

